1. Field of the Invention
This invention relates to a structure and a method of mounting a branch connector to a longitudinally intermediate part of a flat circuit such as a flexible flat cable (FFC) or a flexible printed circuit (FPC).
2. Description of the Related Art
As an example of a structure in which a branch connector is mounted to a longitudinally intermediate part of a flat circuit, a structure described in Japanese Patent Laid-Open Publication No. Hei-10-321273 is known.
In the structure, terminals are disposed perpendicularly to the front side of a flat circuit and connected to conductors of the flat circuit. The terminals are held in a housing of a branch connector arranged on the front side of the flat circuit. The housing is screwed and fixed to a stay which is disposed on the rear side of the flat circuit.
In the structure described in the above publication, the terminals are disposed perpendicularly to the flat circuit and connected thereto, and then held in the housing of the branch connector. The branch connector is thus mounted to the flat circuit, perpendicularly jutting therefrom. When a flat wiring layout is desired with the flat circuit and the branch connector all included, the branch connector part lacks in compactness.
This invention has been achieved with such points in mind.
It is therefore an object of the invention to provide a structure and a method of mounting a branch connector to a flat circuit, in which the flatness of the flat circuit is exploited to provide a flat wiring layout including the branch connector.
According to a first aspect of the invention, there is provided a structure of mounting a branch connector to a flat circuit, comprising: a branch connector having a connector housing; terminals being held in the connector housing of the branch connector; and a flat circuit having conductors in a longitudinally intermediate part of the flat circuit, the conductors being connected to the terminals, the flat circuit being arranged in parallel with the branch connector; wherein, the flat circuit is folded in two in the vicinity of the connected portion in the connector housing; and the folded portion of the flat circuit is housed in the connector housing.
According to a second aspect of the invention, as it depends from the first aspect, the flat circuit is folded in two so that one part is overlaid on the connected part.
Thus in this invention, the terminals and the folded part of the flat circuit may be held in the connector housing after connecting the terminals and the flat circuit, or the flat circuit may be folded in two after connecting the conductors of the flat circuit to the terminals which have previously been held in the connector housing.
In this structure, the terminals are disposed in parallel relationship with the flat circuit to be connected to the conductors, thereafter the flat circuit is folded in two to be overlaid on the connected part, and the folded part together with the terminals are held in the connector housing. Thus unlike a conventional structure in which a branch connector is attached to the flat circuit in the form of perpendicularly jutting therefrom, the flat circuit can be mounted to the branch connector in a parallel relationship so that the structure of the flat circuit and the branch connector is flat form and compact form such that a connector might be mounted to a terminal of a flat circuit. Thus the flatness of the flat circuit is exploited to realize a flat wiring layout including the branch connector.
Although the folded flat circuit is ultimately held in the connector housing, it is a sheet of the flat circuit which is connected to the terminals. Thus when the conductors of the flat circuit is press-connected to the terminals, or when pins provided at the terminals are stuck into the conductors of the flat circuit for conduction, the conductors and the terminals can be connected without applying too much load to the contact blades or pins.
In this regard, it is technically possible that the flat circuit is folded in two and thereafter the folded part is press-connected to the contact blades, or pins are stuck into the folded part for conduction. However this produces too much load to the contact blades or the pins, widening the blades or bending the pins.
Thus as described above, connecting the conductors and the terminals in a state where the flat circuit is in a sheet can eliminate the possibility of widening the contact blades or bending the pins, thereby to provide a positive and stable connection.
According to a third aspect of the invention, as it depends from the first or the second aspect, the terminals are press contact terminals with press contact blades to which the conductors in the longitudinally intermediate part of the flat circuit are press-connected.
Thus in this invention, the connection between the conductors and the terminals are ensured with ease when the conductors have a circular cross section.
According to a fourth aspect of the invention, as it depends from one aspect among the first to the third aspect, the connector housing includes a housing body with a plurality of terminal housing chambers and a cover coupled to the housing body with a hinge, and the terminal housing chamber holds the terminals and the cover is put over the housing body with the folded part of the flat circuit being held in the housing body.
Thus in this invention, since the connector housing includes the connector body and the cover, it is easy to connect the conductors of the flat circuit to their respective terminals all of which have previously been set in their respective terminal housing chambers of the housing body with the cover opened. After connecting the terminals and the flat circuit, the cover is laid over the housing body, thereby to hold the folded part of the flat circuit in the connector housing without undue stress. In particular, the cover is hinged to the housing body, the cover is tilted on the hinge to automatically fold the flat circuit without another folding step, which simplifies the mounting operation.
According to a fifth aspect of the invention, as it depends from one aspect among the first to the fourth aspect, the terminals adjacent to each other are divided with barrier plates formed integrally with the connector housing, and the flat circuit is provided with slits in its insulator, in which slits the barrier plates are inserted.
Thus in this invention, since the barrier plates are inserted into the slits formed in the insulator of the flat circuit, the insulation between the terminals is improved in reliability with the barrier plates. The barrier plates do not hinder the operation of connecting the flat circuit to the terminals.
According to a sixth aspect of the invention, there is provided a method of mounting a branch connector to a flat circuit comprising the steps of housing press contact terminals corresponding to conductors of the flat circuit in terminal housing chambers of a connector housing which includes a housing body with the terminal housing chambers and a cover coupled to the housing body to cover a top surface opening of the terminal housing chambers, placing a longitudinally intermediate part of the flat circuit in a sheet above the top surface opening of the terminal housing chambers, and press-connecting the conductors of the flat circuit to the press contact terminals within the terminal housing chambers, using a press contact jig, and folding the flat circuit in two in the vicinity of the connected part so that one part is overlaid on the connected part, and sandwiching the folded part between the cover and the housing body to hold it in the connector housing.
Thus in this invention, since the flat circuit is press-connected to the press contact terminals held in the terminal housing chambers of the housing body with the press contact jig, the conductors of the flat circuit can be easily connected to the press contact terminals. Thereafter the flat circuit is folded in two to be overlaid on the connected part and the folded part is sandwiched between the cover and the housing body to be held in the connector housing. This keeps the folded state (a U-turn state) without undue stress, protecting the connected part.
Further, since the folded part is held in the connector housing, unlike the conventional structure in which a branch connector is attached to a flat circuit in the form of perpendicularly jutting therefrom, the branch connector can be mounted to the flat circuit in the flat and compact form like a connector to be mounted to a terminal of a flat circuit. Thus the flatness of the flat circuit is exploited to enable a flat wiring layout including the branch connector.
Furthermore, since the press-connecting the flat circuit to the terminals is performed on the flat circuit in a sheet, the press contact blades are not subjected to too much load in press-contacting the conductors and the terminals, preventing widening the press contact blades, which improves reliability in connection.
According to a seventh aspect of the invention, as it depends from the sixth aspect, the cover is coupled to the housing body with a hinge at the fold side of the flat circuit, the cover is swung on the hinge to fold the flat circuit in two, and the folded part is sandwiched between the cover and the housing body to be held in the connector housing.
Thus in this invention, since the cover is tilted on the hinge to fold the flat circuit, the flat circuit is easily folded in the housing. This eliminates another process step of folding the flat circuit, simplifying the mounting operation.